Mike Grudić

Theoretical Astrophysicist

I'm Mike, an astrophysicist at the Flatiron Institute Center for Computational Astrophysics. Here you'll find all things about me and my science.


email: mike dot grudic at gmail dot com
bluesky: @mikegrudic.bluesky.social

Publications

Research

I like to work on a variety of problems in astrophysics, with a focus upon numerical simulations and computational theory.

Star Cluster Formation

The main problem I've worked on is how stars and star clusters form in giant molecular clouds. Gravity, MHD, atomic/molecular physics, and crucially stellar feedback all play a role, and we can use numerical simulations to disentangle these physics. These processes are a key uncertain piece of microphysics in galaxy formation, and give rise to the population of globular clusters, which carry important clues about our Galaxy's ancient history.

Numerical Methods

I like to come up with ways to make astrophysical simulations more realistic, more efficient, and more adaptive.

The IMF

The initial mass function of stars is a fundamentally important quantity in practically all fields of astrophysics. In my own work on GMCs and star clusters, the details of where and how individual stars form are now the leading-order uncertainty. And yet what physics are responsible for it, and how it is expected to vary, remain deeply uncertain. My collaboration is working on the next generation of self-consistent star formation simulations, which will serve as a virtual laboratory for mapping out the physical origins of the IMF in realistic GMCs.

Giant Molecular Clouds

Giant molecular clouds are the progenitors of stars and star clusters in our Galaxy. I would like to understand their lifecycle: how they form, how their properties influence star formation, and how they disperse.

Turbulence

Most baryonic matter in the Universe is in a state of magnetohydrodynamic turbulence. I want to understand how the properties of astrophysical systems emerge from the behaviour of turbulence. Particularly important for star formation is understanding exactly how gravity and feedback alter and drive turbulence.

Galaxy formation

I am a regular contributor to the FIRE collaboration, working on high-resolution cosmological zoom-in simulations that resolve the multi-phase ISM and stellar feedback processes. I am using my high-resolution GMC simulations to calibrate the next generation of star formation prescriptions, extending galaxy simulations' predictive power into dense gas.

Software

I am a perpertual tinkerer and wheel-reinventor: having a hard time trusting black boxes, I try and learn the guts of computational techniques and do them myself. Sometimes usable software is the product. Sometimes it's even good! If you have any suggestions or questions about any of these, please don't hesistate to get in touch. Most of my codes have benefited greatly from community feedback.

pytreegrav

pytreegrav is a fast, OpenMP-parallel Barnes-Hut style tree-code for computing gravitational potentials and fields from particle data implemented entirely in python. With numba as its backend, it can crunch forces/potentials at a rate that is nearly competitive with state-of-the-art N-body codes.

meshoid

meshoid (MESHless Operations such as Integrals and Derivatives) is a multi-purpose tool for performing a variety of useful operations for analyzing or visualizing meshless or unstructured mesh simulation data.

MakeCloud

MakeCloud is an initial conditions generator for GMC simulations, which can include initial turbulent velocity and magnetic fields with an arbitrary mixture of compressive and solenoidal modes. Compressive magnetic fields not recommended.

CloudPhinder

CloudPhinder uses an algorithm related to the Subfind algorithm to identify self-gravitating gas structures (ie. the progenitors of star clusters) in galaxy simulation data.

SinkVis

SinkVis is my collaboration's in-house visualization tool for making images and movies of star formation simulations, with meshoid's projection/deposition routines as its backend.

GIZMO

I am a frequent contributor to the GIZMO multi-method astrophysical radiation MHD code, mainly working on its sink particle and feedback coupling algorithms for star formation and cosmological black hole simulations.

About Me

Me in a happy place.

I come from the island of Newfoundland in Canada. I never much cared for science until my first year of university, when I was inspired by Carl Sagan, Stephen Hawking, Richard Feynman (I know, I know) and my first look at the Orion Nebula through a telescope. From then on I was hooked on physics and astronomy. I switched to a joint degree in physics and applied mathematics at Memorial University of Newfoundland, completing my undergraduate dissertation on relativistic gravitational scattering with Dr. John Lewis. I then went to grad school at Caltech and got into star formation theory while working with Dr. Phil Hopkins, eventually resulting in my doctoral dissertation, "The Role of Stellar Feedback in Star Cluster Formation". As a postdoctoral fellow at Northwestern University I co-founded STARFORGE with my grad school buddy David Guszejnov, and I carried on this work as a Hubble Fellow at Carnegie and now as an Associate Research Scientist - Software at Flatiron!

I try to practice uncompromised honesty and candor in my science. We are tackling tough problems not to be solved overnight, with an endless supply of dead-ends that get the right answer for the wrong reasons. For me, the best approach is to stay grounded, be realistic about the limitations of our models, and apply physical intuition and thought experiments to the code and equations.

When not being a physicist or a computer-toucher I'm basically the exact opposite doing caveman things. Pick up heavy stones on stick. Sleep in woods. Walk up big mountain. Is good, make happy ooga booga.